The present invention pertains generally to the field of heart valve repair. More specifically, the present invention pertains to a device and method for the reduction of myocardial wall tension and the repair of mitral valve insufficiency.
Dilated cardiomyopathy is often accompanied by mitral valve insufficiency. There are several reasons for the presence of mitral valve insufficiency associated with a dilated heart. First, chamber dilation and associated high wall stresses increase the diameter of the mitral valve annulus. Additionally, as the heart dilates, the positioning of the papillary muscles is altered. Papillary muscles and chordae in a dilated heart will have moved both radially away and down from the mitral valve. This rearrangement of the vascular apparatus and enlargement of the annulus prevent the valve from closing properly.
Currently mitral valve insufficiency is treated by either repairing or replacing the valve. Surgical procedures used to repair the valve including ring posterior annuloplasty which consists of sewing a C or D-shaped ring around the posterior leaflet of the mitral valve and drawing in the annulus, reducing its previously enlarged diameter. Another method is to approximate the anterior and posterior mitral leaflets (Alfieri repair) by placing one suture through the center of both leaflets. This gives the valve a figure 8-shaped appearance when the valve is opened. When the mitral valve is replaced, the original leaflets are removed and the chordae are cut. An artificial valve consists of mechanical or tissue leaflets suspended on struts attached to a metal stent, and is sutured into place on the mitral annulus.
It has been argued that valve repair is preferable to valve replacement if the leaflet-chordae-papillary connections can be maintained. Heart wall stress will increase if the chordae are cut during valve replacement. It has been shown that by severing the chordae there can be 30 percent (30%) reduction in chamber function. Mitral valve replacement has high morality in very sick, chronic heart failure patients.